Hikari Kohinata is the story's first protagonist. She is a student at Yumegaoka High School and is in year 1, class 2. She spends most of her time with her grandma at the beach. She loves diving and tonjiru (miso pork soup). She wear a diver's safety whistle on her neck. She likes to give people nicknames. She was the one that decided on "Dotty" and "Cha."